Among cancer patients, major depression is the most common psychiatric disorder (13-56%), with the majority of patients presenting to primary care for mental health treatment. For most of these patients, treatment satisfaction is low and response rates are less than anticipated by Federal Health Care Policies and Guidelines. Thus, the need to focus on quality improvement has been highlighted. The primary objective of the study is to explore the potential effectiveness of a cognitive-behavioral activation treatment for depression (CBATD) for depressed cancer patients in primary care. Based on encouraging preliminary outcome data with a behavioral activation intervention, this study explores whether supplementing BATD with additional cognitive-behavioral treatment components (CBATD) better addresses the unique (and complex) symptom patterns of depressed cancer patients and improves treatment outcome. The CBATD protocol may be a viable means to improve quality of care and quality of life for cancer patients in that it addresses primary symptoms of cancer and depression and may reduce practical problems associated with mainstream primary care interventions for depression. This research is important considering the paucity of psychosocial treatment outcome work with depressed cancer patients, methodological limitations of studies, lack of effectiveness research in "real-world" (primary care) settings where most patients present with depression, and limitations of existing psychosocial treatments in this context. The design involves the collection of pilot data within a small open trial (N = 20). The effects of CBATD at post-treatment and 3-month follow-up will be evaluated using clinical, functional, satisfaction, and service utilization outcome measures. Clinical outcomes include measurement of target symptoms (depression) and potentially coexistent clinical conditions (i.e., anxiety, substance use). Functional outcomes assess functional status, medical outcomes, social support, and quality of life. Satisfaction outcome examines patient satisfaction with CBATD. The project is an important first step toward developing a large-scale, multi-site, randomized efficacy-effectiveness study that assesses the clinical utility of CBATD in treating depressed cancer patients in primary care compared with alternative (psychosocial and pharmacological) interventions for depression.